1. Field
Embodiments relate to a heat pump type clothes dryer.
2. Description of the Related Art
As an example of a conventional clothes dryer, Japanese Unexamined Patent Publication No. 61-22894 discloses a heat pump type dryer (see FIG. 1). In the disclosed heat pump type dryer, a condenser (radiator) is provided at an air suction or intake line, which sucks or intakes air into a drum. Also, a fan and a heat absorber (evaporator) are provided at an air exhaust line, through which air is exhausted from the drum. In accordance with this configuration, the heat pump type dryer recovers exhaust heat from the exhaust air, and heats the sucked or intake air using the recovered heat.
However, in the configuration in which the fan is installed at the air exhaust line, as mentioned above, the interior of the drum may be under a lower pressure than atmospheric pressure. As a result, ambient air is sucked into the drum through gaps formed in the lines. For example, air may be sucked between sliding parts of the drum, or through connecting portions of other elements, due to a pressure difference between the drum and the outside of the drum. In particular, in the heat pump type dryer mentioned above, the radiator provided at the air suction or intake line exhibits high flow resistance, so that suction or intake of ambient air through the gaps may be increased. Consequently, the flow rate of air passing around the radiator provided at the air suction or intake line is reduced. In a heat pump cycle, when the flow rate of air passing around a radiator is reduced, the pressure of refrigerant may be increased. Accordingly, when the flow rate of air passing around the radiator is reduced, it may be necessary to reduce heating capacity, and thus to reduce drying capacity.
In order to secure a required air flow rate for the radiator, the blowing rate of the fan installed at the air exhaust line may be increased. However, when the flow rate of exhaust air increases, the pressure loss of the air exhaust line may also be increased, because an air exhaust duct is connected to the dryer, as shown in FIG. 2. Generally, pressure loss is increased in proportion to the square of the air flow rate increase ratio, and air blowing power is increased in proportion to the cube of the air flow rate increase ratio. For this reason, there may be problems such as increased power consumption and increased noise of the fan.